1. Technical Field
The present invention relates to technology of performing mutual authentication between a controller and device connected to a network, and sharing a group key.
2. Description of the Related Art
As of recent, there is expectation for services using various types of history information collected from devices and the like (hereinafter referred to simply as “devices”) such as home appliances, audio and visual (AV) devices, household equipment, and so forth, that have network connection capabilities, and collected in a server in a cloud.
A conceivable arrangement in such a service is to establish a device that controls devices in the home (hereafter referred to as “controller”), and the controller to relay communication between the devices and the server in the cloud. In doing so, it is required that the connection between the controller and the device prevent information from leaking, such as spoofing by unauthorized devices and interception of communication contents.
An example of countering spoofing by unauthorized devices that is performed includes authentication of the legitimacy of controllers and devices using public key infrastructure (PKI). An example of countering information leakage is encrypted communication being performed between controllers and devices of which the legitimacy has been authenticated sharing a key for encrypted communication.
In a case where there are multiple devices connecting to a controller, the controller and the devices sharing the same key for encrypted communication (hereinafter referred to as “group key”) enables encryption of multicast communication and broadcast communication where the controller transmits the same information to the devices at once.
For description of this technology, see Japanese Patent No. 4576997, Federal Information Processing Standards Publication (FIPS PUB) 186-4: Digital Signature Standard (DSS), National Institute of Standards and Technology (NIST), July 2013, and NIST Special Publication 800-56A Revision 2: Recommendation for Pair-Wise Key Establishment Schemes Using Discrete Logarithm Cryptography, National Institute of Standards and Technology (NIST), May 2013.